Automatic stoker apparatus



'April 17, 1934. x B; D. WETMORE 1,954,856

AUTQMA'IIC STOKER APPARATUS Filed Juhe 20, 1927 w i I I I 2206 7%1 Patented Apr. 1 7, 19 34 PATENT OFFICE AUTOMATIC STOKER APPARATUS Bert Daniel Wetmore, Bismarck, N. Dak., as-

signor to Henry M. Brooks, New York, N. 1., William Tudor Gardiner, Augusta, Maine, and Richard Kingsley Hawes, Fall River, Mass.,

trustees Application June 20, 1927, Serial No.'199,877

6 Claims.

This invention relates to an apparatus for preventing the escape of smoke, gas or dust from an automatic stoker back into the fireroom. v

Heretofore, in operating an automatic stoker, especially whenever the feed pas age between the hopper and furnace became empty for any reason smoke, gases and dust were likely to escape from the furnace back through the hopper into the iireroom.

It is accordingly the principal object of this invention to provide an apparatusfor preventing the; escape of gases and dust into the fireroom through the feed passage of an automatic stoker or the like.

It is also an object of this invention to provide an arrangement for preventing the escape of gases into the fireroom which may be conveniently incorporated in the apparatuses now in use for automatically feeding fuel to furnaces.

Other and further objects of this invention will be apparent as the same becomes better understood from an examination of the specification and claims in connection with the accompanying drawing wherein Fig. 1 is a fragmentary longitudinal sectional view of a boiler proVided With a stoker of the type to which this invention relates, and an arrangement embodying this invention.

Fig. 2 is an end view of the same.

Referring to the drawing more particularly,

numeral 3 represents the interior of the furnace in a boiler 4. The coal or other fuel is adapted to be fed to the furnace 3 by means of the stoker represented generally by the reference numeral 5. The stoker 5 includes a feed passage 6 adapted to discharge into a diverging mouth 7 beneath the bottom of the furnace compartment 3. The outer end of the passage 6 communicates with the bottom of a hopper 8 by means of which coal or other fuel is admitted 'to said passage. screw 9 is mounted longitudinally within the passage 6 and is driven through the intermediary of reduction gearing 10 by a. motor 11. An air passage 12 surrounds the passage 6 and is adapted to deliver air to the furnace 3, and more particularly to deliver the combustion air to the fuel rising from 6.

. The outer end of the passage 12 is connected to the discharge of a blower 13 also driven by the motor 11. V p

All of the parts just described are old and well ,known in the'art. In the. operation of these parts the coal or other fuel is suppliedto the hopper 8 and thence is fed through the passage 6 to the furnace 3 by the revolving screw 9. It fre- A feed stoker that the feed passage 6 becomes empty. In such a case smoke or other gases are likely to leak back through the passage 6 into the fireroom. It has been discovered also that some: times air or other gases pass backthrough passag 6 even when the latter is not empty.

In order to overcome this difficulty I arrange, for the blower 3 to draw air across a surface, as it were, of the coal in the fuel supply system, and to this endpreferably provide an angular hood. 14 above the intake of ,the hopper 8 and connect the top of this hood by means of a. pipe connection 15 to the intake 16 of the blower 13. The

vertical side 17 of the hood 14 is left open so that coal or other fuel may be admitted to the hopper. By means of the hood l4 and the connection therefrom to the intake of the blower 13 any smoke or other gases are returned through the air passage 12'to the furnace 3 together with all dust made in filling the hopper 8.

The pipe 18 which is connected, as shown in Fig. 1, to the delivery side of the blower may be utilized for blowing a stream of air into the fuel feeding passage 6 at the inner end thereof toward the fire box to cause a positive flow of air in the passage toward the fire box. This arrangement provides further assurance against the leaking of gases outwardly through the pas-' sage toward the hopper.

It will be apparent that the aforedescribed improvement may be conveniently and readily incorporated in automatic stokers or like apparatus now in use. I

I am aware that many changes may be made throughout a wide range without departing from the principle of this invention and I. therefore do not wish to be limited to the details shown or described.

I claim:

1. The combination of a furnace having a fire box and a stoker including a fuel passage leading to the fire box, a feed hopper on the outer end of said passage normally open to the atmosphere and to said passage, a blower and conduits connected thereto arranged for delivering air to said furnace and arranged to induce a flow of air from the atmosphere across the inlet of the hopper.

2. The combination of a furnace having a fire box and a stoker including a fuel feed passage leading to the fire box, a feed hopper on the outer end of said passage in open communication therewith and normally open to the atmosphere,- means including a conduit connected with the hopper for causing a positive flow of air across the inlet of the hopper and into the fire box and, congases from the passage into the fire box and forpreventing their escape into the atmosphere.

3. The combination of a furnace having a fire box and a stoker including afuel passage leading to the fire box, an upwardly extending hopper on the outer end of said passage, a hood over said hopper open to the atmosphere and providing communication from the atmosphere directly through the hood and hopper to said passage, a blower and conduits connected thereto and with fire box and hood constructed to induce air flow from the atmosphere through the hood across the top of said hopper and to deliver said air into the fire box.

4. The combination of a furnace having a fire box, a stoker including a fuel feed passage leading to the fire box, an upwardly extending hopper on the outer end of said passage open directly to the atmosphere, a hood over said hopper, a blower and conduits connected thereto and with the furmace and hood constructed to intake air through said hood across the top of said hopper and de- 1,954,sse

liver the air into said furnace, and a pipe connected with the blower for directing air into said passage near the inner end thereof toward said fire box.

5. The combination of a furnace having a firebox, a coal stoker including a passage for coal leading to the firebox, a coal hopper at the outer end of said passage normally open adjacent its upper end and open to said passage to supply coal to the latter, a blower, and a conduit system for said blower, said conduit system including an inlet conduit leading to the inlet of said blower and a second conduit leading from said blower to said firebox to supply combustion air to the latter, and a hood at the inlet end of said inlet conduit, said hood extending over said open upper end of said hopper externally of said hopper and being open to admit air to said inlet conduit.

6. The subject matter of claim 5, characterized by the fact that said inlet conduit is so connected to said inlet of said blower that substantially all the air entering said blower passes through said inlet conduit.

' BERT DANIEL WETMORE. 

